feat: implement getrecent blocks

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.3.0.0] - 2024-10-14
+
+- `getrecentblocks` endpoint
+
 ## [0.2.0.0] -- 2024-10-11
 
 ### Added

exblo-server.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.4
 name:               exblo-server
-version:            0.2.0.0
+version:            0.3.0.0
 -- synopsis:
 -- description:
 homepage:           https://vergara.tech/exblo

src/Server.hs

@@ -10,16 +10,17 @@
 
 module Server where
 
+import Control.Monad (forM)
 import Control.Monad.IO.Class (liftIO)
 import Data.Aeson
 import qualified Data.ByteString.Char8 as C
 import qualified Data.ByteString.Lazy as LBS
+import Data.Either (fromRight, isRight)
 import Data.HexString
 import Data.Scientific (scientific)
 import qualified Data.Text as T
-import qualified Data.Text.Encoding as TE
 import Servant
-import Types (ExbloInfo(..))
+import Types (ExbloInfo(..), ShortBlock(..))
 import ZcashHaskell.Types
   ( BlockResponse(..)
   , RawZebraTx(..)
@@ -39,14 +40,57 @@ type ExbloAPI
       '[ JSON]
       Transaction -- gettransaction
      :<|> "getinfo" :> Get '[ JSON] ExbloInfo -- getinfo
-     :<|> "getblockinfo" :> Capture "blkid" T.Text :> Get '[ JSON] BlockResponse
+     :<|> "getblockinfo" :> Capture "blkid" T.Text :> Get '[ JSON] BlockResponse -- getblockinfo
+     :<|> "getrecentblocks" :> Get '[ JSON] [ShortBlock]
 
 api :: Proxy ExbloAPI
 api = Proxy
 
 exbloServer :: Server ExbloAPI
-exbloServer = handleBlockheight :<|> handleTx :<|> handleInfo :<|> handleBlock
+exbloServer =
+  handleBlockheight :<|> handleTx :<|> handleInfo :<|> handleBlock :<|>
+  handleRecentBlocks
   where
+    handleRecentBlocks :: Handler [ShortBlock]
+    handleRecentBlocks = do
+      res <-
+        liftIO $ do
+          s <- makeZebraCall "localhost" 18232 "getblockcount" []
+          let blkList = do
+                findBlocks =<< s
+          return blkList
+      case res of
+        Left e -> throwError $ err400 {errBody = LBS.fromStrict $ C.pack e}
+        Right sb -> liftIO sb
+    findBlocks :: Int -> Either String (IO [ShortBlock])
+    findBlocks x = do
+      let blks = [(x - 10) .. x]
+      let res =
+            forM blks $ \y -> do
+              s1 <-
+                makeZebraCall
+                  "localhost"
+                  18232
+                  "getblock"
+                  [Data.Aeson.String $ T.pack $ show y, jsonNumber 1]
+              s2 <-
+                makeZebraCall
+                  "localhost"
+                  18232
+                  "getblock"
+                  [Data.Aeson.String $ T.pack $ show y, jsonNumber 0]
+              let blocktime = getBlockTime <$> s2
+              let blhash = bl_hash <$> s1
+              let blk = ShortBlock y <$> blhash <*> blocktime
+              return blk
+      let resList = catRights <$> res
+      pure resList
+    catRights :: [Either a ShortBlock] -> [ShortBlock]
+    catRights [] = []
+    catRights (x:xs) =
+      if isRight x
+        then fromRight (ShortBlock 0 (hexString "deadbeef") 1) x : catRights xs
+        else catRights xs
     handleBlock :: T.Text -> Handler BlockResponse
     handleBlock i = do
       s <-
@@ -80,10 +124,10 @@ exbloServer = handleBlockheight :<|> handleTx :<|> handleInfo :<|> handleBlock
                   (bl_txs br)
     handleBlockheight :: Handler Int
     handleBlockheight = do
-      s <- liftIO $ makeZebraCall "localhost" 18232 "getblockchaininfo" []
+      s <- liftIO $ makeZebraCall "localhost" 18232 "getblockcount" []
       case s of
         Left e -> throwError $ err400 {errBody = LBS.fromStrict $ C.pack e}
-        Right bci -> return $ zgb_blocks bci
+        Right bci -> return bci
     handleTx :: HexString -> Handler Transaction
     handleTx i = do
       s <-
@@ -120,7 +164,7 @@ exbloServer = handleBlockheight :<|> handleTx :<|> handleInfo :<|> handleBlock
             Left e1 ->
               throwError $ err400 {errBody = LBS.fromStrict $ C.pack e1}
             Right bci ->
-              return $ ExbloInfo (zgb_net bci) (zgi_build bi) "0.1.0.0"
+              return $ ExbloInfo (zgb_net bci) (zgi_build bi) "0.3.0.0"
 
 exbloApp :: Application
 exbloApp = serve api exbloServer

src/Types.hs

@@ -5,13 +5,22 @@ module Types where
 
 import Data.Aeson
 import Data.Aeson.TH (deriveJSON)
+import Data.HexString
 import qualified Data.Text as T
 import ZcashHaskell.Types (ZcashNet)
 
 data ExbloInfo = ExbloInfo
-  { ex_net :: ZcashNet
-  , ex_zebra :: T.Text
-  , ex_version :: T.Text
+  { ex_net :: !ZcashNet
+  , ex_zebra :: !T.Text
+  , ex_version :: !T.Text
   } deriving (Eq, Show)
 
 $(deriveJSON defaultOptions {fieldLabelModifier = drop 3} ''ExbloInfo)
+
+data ShortBlock = ShortBlock
+  { sb_height :: !Int
+  , sb_hash :: !HexString
+  , sb_time :: !Int
+  } deriving (Eq, Show)
+
+$(deriveJSON defaultOptions {fieldLabelModifier = drop 3} ''ShortBlock)